1. Field of the Invention
The present invention relates to electromagnetic air pumps and, more particularly, to an electromagnetic air pump having a resinous air tank for temporarily storing compressed air.
2. Description of the Related Art
An electromagnetic air pump has a pump unit having an electromagnetic drive section to suck in air from the surroundings and to compress the air and an air tank for temporarily storing the compressed air from the pump unit to remove pulsation caused in the compressed air by the pump unit before discharging the compressed air.
Air compressed by the air pump is heated to a considerably high temperature by adiabatic compression. Therefore, the air tank needs to be capable of effectively performing heat dissipation. For this purpose, for example, a space for heat dissipation is provided between the air tank and the pump unit (see Patent Literatures 1 and 2 noted below).    Patent Literature 1: Japanese Patent No. 3485478    Patent Literature 2: Japanese Examined Utility Model Application Publication No. Hei 4-41267 (1992-41267)
Some air pumps have a resinous air tank to reduce the weight thereof. Such air pumps suffer, however, from the following problems.
Resinous air tanks are more difficult to dissipate heat from than metallic air tanks. Accordingly, one conventional practice is to assemble the air tank and the pump unit away from each other so that a space for heat dissipation is formed therebetween. However, it is a complicated operation to assemble the air tank to the pump unit as stated above. In addition, the resinous air tank is likely to be thermally deformed when used for a long period of time, and such deformation of the air tank may impair air-tightness relative to the air pump.
An object of the present invention is to provide an electromagnetic air pump using a resinous air tank to achieve a weight reduction and yet free from the above-described problems.